A cross-sequential study of theory of mind, IQ, and fair sharing framed socially and non-socially in young children

Both ability and motivation underlie uniquely human prosociality but the study of resource allocation in young children has focused on prosocial motivations rather than mathematical ability to fairly allocate rewards. We examined the development of fair sharing by testing 3–6YO children at two time points (N at Time 1 = 158, N at Time 2 =111) with ToM, IQ, fractional quantities (proper or improper fraction problems), and framing of the problem (social or non-social) as predictors of children’s performance. As expected, children performed better with time and age, and on proper versus improper fractions. However, in contrast to our predictions, performance was not consistently related to general IQ, ToM, or framing of the problem although ToM interacted with age and framing to predict performance. Our results suggest that it is important to consider limitations in numerical ability rather than assuming selfish motivations when young children fail to share fairly.